Neuroscience 1 Pause for thought: Probably 100 million neurones fire during skilled movements.

Divisions of the Nervous System

Parkinson’s Disease & Basal Ganglia

Posture, Stance and Gait Posture: position of body. Standing, sitting, kneeling & lying (supine or prone) Stance (Station): Gait - locomotion Movement Disorder can be recognised by disruption of any combination of posture, stance or gait.

Classification of Movement Disorders Hypokinetic – slow/poor movements Bradykinesia, Freezing Rigidity, Postural instability Hyperkinetic – fast/excessive movements Rhythmic – tremors Non-rhythmic – purposeless, irregular movements Not mutually exclusive eg Parkinson’s Disease has both hypo- and hyperkinetic movements

Parkinson’s Disease Parkinson's Disease (PD) is a progressive neurological condition affecting movements such as walking, talking, and writing. It is named after Dr. James Parkinson ( ), the London doctor who first identified PD as a specific condition. Etiology (Cause) – UNKNOWN. The symptoms of PD have three primary features: Resting Tremor - which usually begins in one hand. This is the first symptom for 70% of people with PD Slowness of movement (bradykinesia) - people with Parkinson's may find that they have difficulty initiating movements or that performing movements takes longer. Stiffness or rigidity of muscles - problems with activities such as standing up from a chair or rolling over in bed may be experienced. Various non-motor symptoms may also be experienced, for example: sleep disturbances constipation urinary urgency depression

Parkinson’s Disease PD is found all over the world. Exact global figures are not always available, though it is estimated that four million people worldwide have the condition. Generally, in the UK: one in 500 people, around 120,000 individuals, have PD about 10,000 people in the UK are diagnosed each year statistically, men are slightly more likely to develop PD than women (Essential Tremor – estimated that 1.4 million people in UK are affected). The risk of developing PD increases with age, and symptoms often appear after the age of 50. Some people may not be diagnosed until they are in their 70s or 80s. However, in some cases PD is diagnosed before the age of 40, and this is known as young- onset PD. If PD is diagnosed before the age of 18, it is known as juvenile Parkinson's, although this is extremely rare.

Parkinson’s Disease

Motor Cortex, Basal Ganglia and Thalamus form a Motor Loop Motor Cortex Area 6 Motor Cortex Area 4 Thalamus VLo Basal Ganglia Motor Cortex Area 4 Motor Cortex Area 6 Thalamus VLoBasal Ganglia Midline Muscle activation

The Four Nuclei of the Basal Ganglia Striatum comprising: caudate nucleus and putamen Globus pallidus (or pallidum) comprising: external (or lateral) and internal (or medial) segments. GPe and GPi Subthalamic nucleus (STN) Substantia nigra comprising: pars reticuluta and pars compacta SNr and SNc Functional Aspects: Striatum – Input stage of the Basal Ganglia. GPi/SNr – Output stage of Basal Ganglia. SNc – Regulates neural behaviour between Striatum and GPi/SNr.

Organisation of the Basal Ganglia & Motor Output Basal Ganglia Excitatory Inhibitory Striatum contains spiney neurons. D1 - neurons which are excited by Dopamine. D2 – neurons which are inhibited by Dopamine. SNc – contains Dopamine neurons. PD is a problem with the SNc. 4 6

Substantia nigra Normal PD Normal PD Neuromelanin No Neuromelanin

Basal Ganglia PD Basal Ganglia Normal 4 6

Chronic High Frequency Deep Brain Stimulation for Tremor Stereotaxically placed electrode into the subthalamic nucleus Subcutaneous leads Remote controlled battery operated stimulator

Deep Brain Stimulation ON/OFF/ON

Fetal Transplantation

Goodwin VA, Richards SH, Taylor RS, Taylor AH, Campbell JL. (2008) The effectiveness of exercise interventions for people with Parkinson's disease: A systematic review and meta-analysis. Mov Disord. 23: Physical Exercise Yoon MC, Shin MS, Kim TS, Kim BK, Ko IG, Sung YH, Kim SE, Lee HH, Kim YP, Kim CJ. (2007) Treadmill exercise suppresses nigrostriatal dopaminergic neuronal loss in 6-hydroxydopamine-induced Parkinson's rats. Neurosci Lett. 423: Crizzle AM, Newhouse IJ. (2006) Is physical exercise beneficial for persons with Parkinson's disease? Clin J Sport Med. 16: VIDEO LINK &ei=U1OuSdy2AZGgqgLzyojdDg&q=parkinson%27s+ disease&hl=enhttp://video.google.co.uk/videoplay?docid= &ei=U1OuSdy2AZGgqgLzyojdDg&q=parkinson%27s+ disease&hl=en